Numerous studies support the hypothesis that children of parents with affective disorders are at increased risk for psychiatric disorders, especially depression. Building on the investigative team's experience in the treatment and prevention of adolescent depression, this investigation examines the clinical efficacy and cost-effectiveness of a innovative service model for intervening with adolescent offspring of depressed adults enrolled in a health maintenance organization. A multiple gating assessment and intervention procedure will be employed, in which a series of progressively more intensive interventions are matched to increasingly more disordered and/or at-risk subjects. Case-finding methods based on HMO pharmacy-record review and HMO automated mental health appointment system will be employed to identify adolescents aged 13 to 18 living in enrolled families in which at least one parent has recently been treated for a major affective disorder with either anti-depressant medication and/or psychotherapy. A randomly selected subset of these families will be recruited in a staggered fashion over a two-year period in a series of 6 cohorts. Based on intake interview, adolescents will be classified into one of three mutually exclusive groups representing increasing severity levels of current depressive symptomatology: (a) a Currently Depressed group, consisting of adolescents with DSM-III-R diagnoses of either major depression and/or dysthymia; (b) a Demoralized group, consisting of adolescents reporting some sub-diagnostic levels of depressive symptoms which are insufficient to meet full criteria for a DSM-III-R affective diagnosis; and (c) a third group consisting of Resilient adolescents with no symptoms or diagnosis of depression, anxiety, or other disorder. Within each cohort, Currently Depressed and Demoralized offspring (total two-year follow-up N=270 for all 6 cohorts) will be triaged to one of two separate randomized outcome trials of intervention levels matched to the level of current psychopathology exhibited. The Currently Depressed individuals will be triaged to a randomized trial comparing a 32-hour, cognitive-behavioral, group psychotherapy treatment to a "usual care" control condition. The Demoralized adolescents will be triaged to a randomized outcome trial comparing a 15-hour preventive group intervention to a "usual-care" control condition. Resilient adolescents will not be entered into an outcome trial, nor will they be followed with intensive interviews. Adolescents in the two outcome trials will be re- interviewed for psychiatric symptomatology and disorder and other dependent variables at 12 and 24 months follow-up. HMO databases will also be reviewed to examine service utilization/cost dependent variables to determine the cost and utility of the intervention model.